1. Field of Invention
This invention relates to a grommet for a door of an automobile. In particular, this invention relates to a grommet that improves waterproofness at a position where a wire harness is mounted to extend from an automobile body to a door body. This invention further relates to a method for mounting the grommet.
2. Description of Related Art
Since water travels along a glass that moves up and down, and intrudes into the interior of right and left door bodies of an automobile, a wire harness mounted to extend from the automobile body to the door body sometimes avoids the interior of the door body and passes through a passenger compartment side. The wire harness mounted as described above, passes through an opening provided in an inner plate portion, which is on a passenger compartment side of the door body, to provide a required connection. Further, a trim cover is mounted to cover an entire surface at the passenger compartment side of the inner plate portion of the door body so that the wire harness is prevented from being exposed to the exterior.
FIGS. 4(A) and 4(B) schematically show a mounting structure of a wire harness extending from the automobile body 1 to the passenger compartment side R of the door body, which is proposed by the Japanese Laid-Open Publication Nos. 7-179156 and 8-40155. In the mounting structure, an L-shaped recess 2c is formed to extend from a side plate portion 2a, which is a front side of the door body 2 and on which a hinge is attached, to an inner plate portion 2b at the passenger compartment side. Further, an attachment member 3 that covers the recess 2c is mounted by using bolts 8.
The attachment member 3 includes an L-shaped plate 4, such as an iron plate or a resin plate, which has a through-hole 4a, and a watertight packing 5 attached on the interior surface (facing the door body) of the L-shaped plate 4. Further, a grommet 6, in which a wire harness W/H is inserted, is mounted at the through-hole 4a. The wire harness W/H extending from the door side of the grommet 6 passes through a space K formed by the attachment member 3 and the recess 2c in the door body 2, and extends toward the passenger compartment side R of the inner plate portion 2b of the door body 2, so as not to pass through the interior 2g of the door body 2, where water is likely to intrude. Further, a weather strip 7 is provided on the side plate portion 2a of the door body 2 so as to pass over the attachment member 3. Further, after the completion of mounting the wire harness, a trim cover 9, which covers the inner plate portion 2b, is attached to the passenger compartment side R of the inner plate portion 2b of the door body 2.
Since the wire harness W/H provided as describe above is formed by bundling a predetermined number of wires, it has a constant (predetermined) cross section. Accordingly, in order to insert the wire harness W/H into the space K formed by the recess 2c of the door body 2 and the attachment member 3, the cross section of the space K should be made larger than the cross section of the wire harness W/H. To make the cross section of the space K larger, two avenues can be considered, i.e., increasing the depth of the recess 2c, or increasing the vertical width of the recess 2c. However, since the door body 2 is formed by press molding, machining to increase the depth of the recess is difficult and requires high cost. Thus, it is more realistic to increase the vertical width of the recess. Accordingly, the width in a vertical direction of the recess 2c is increased so that the wire harness W/H can be inserted therein.
When the vertical width of the recess 2c is increased, it is necessary to increase the vertical width of the attachment member 3, which covers the recess 2c. Generally, the vertical width T of the attachment member 3 is set between 120 and 150 mm. As a result, since an area in which the attachment member 3 is exposed to the exterior becomes large at the side plate portion 2a of the door body 2, the appearance becomes worse. Further, since the weather strip 7 attached on the side plate portion 2a cannot be directly attached to the door body 2 at the position where it crosses over the attachment member 3, the weather strip 7 might lose touch with the wide attachment member 3, and it becomes difficult to ensure waterproofness.
Further, since the attachment member 3 itself is provided with the L-shaped (iron) plate 4, the watertight packing 5 and the grommet 6, the number of parts is large, and thus, the cost becomes high. Further, since the attachment member 3 is mounted on the door body 2 by fastening with the bolts 8, the mounting operation takes a long time. Furthermore, because the path of the wire harness W/H to be mounted requires that it be bent about 90 degrees at two positions, i.e., at the side plate portion 2a and at the inner plate portion 2b of the door body 2, the mounting operation becomes difficult and cannot be performed efficiently. In addition, the wire harness W/H itself, when bent to such an extent, is subject to increased stress. Further, if a gap occurs at the contact point S between the watertight packing 5 and the side plate portion 2a, due to the vibration of the automobile body or age deterioration, etc., water intrudes and splashes on the wire harness W/H, a short or the like might occur in the worst case.
To solve the problem described above, Japanese Laid-Open Publication No.9-76837 proposed a mounting structure of a wire harness (note FIG. 5). In the mounting structure, an opening 2dxe2x80x2 is continuously notched from a side plate portion 2axe2x80x2 to an inner plate portion 2bxe2x80x2 in the passenger compartment side of the door body 2xe2x80x2, and a recessed portion 2exe2x80x2 is provided at the periphery of the opening 2dxe2x80x2 in the side plate portion 2axe2x80x2. Further, a grommet 6xe2x80x2, which is an attachment member of the wire harness, is integrally formed with a weather strip 7xe2x80x2 and has an L-shape. A bellows portion 6bxe2x80x2 extends from a front surface 6axe2x80x2 and the wire harness W/H passing through the bellows portion 6bxe2x80x2 extends toward the side surface (passenger compartment side portion) 6cxe2x80x2. 
In the attachment structure described above, since the weather strip 7xe2x80x2 and the grommet 6xe2x80x2 are formed unitarily in one piece as a single unit, waterproofness is ensured. Further, due to the engaging structure between the grommet 6xe2x80x2 and the door body 2xe2x80x2, the efficiency of mounting of the grommet 6xe2x80x2 to the door body 2xe2x80x2 improves. However, due to the unitary structure of the weather strip 7xe2x80x2 and the grommet 6xe2x80x2, a molding die becomes large and complicated, and the manufacturing costs for the die become very expensive. To engage with the grommet 6xe2x80x2, the recessed portion 2exe2x80x2 is provided, which results in the shape of the cross section of the door body 2xe2x80x2 being complicated. As a result, the cost of machining of the door body 2xe2x80x2 becomes higher. Further, because the wire harness W/H is exposed to the exterior from the bellows portion 6bxe2x80x2 to a passenger compartment side portion 6cxe2x80x2, water that travels along a glass and intrudes into the interior of the door body 2xe2x80x2 may splash on the wire harness W/H.
Accordingly, the present invention is provided in view of the above-described problems, and an objective of the present invention is to reduce the vertical width of the grommet mounted on the door body by diagonally mounting the wire harness from the front surface side to the passenger compartment side of the door body, so as to improve appearance when viewed from the outside and to improve waterproofness.
To achieve the above and/or other goals, the present invention provides a grommet for a door in which a wire harness to be mounted to extend from an automobile body to a door body is to be inserted. The grommet is configured to engage with an opening continuously provided in a front side and a passenger compartment side of the door body. The front side and the passenger compartment side connect with each other at a predetermined angle. The grommet includes a bellows portion into which the wire harness is to be inserted, a door mounting base portion, and an automobile mounting base portion configured to engage with the automobile body. The automobile mounting base portion extends past an end of the bellows portion. The door mounting base portion includes a front side portion from which the bellows portion extends and that covers the opening in the front side of the door body, a passenger compartment side portion that connects with the front side portion at the predetermined angle and covers the opening in the passenger compartment side of the door body and having a wire inserting through-hole, and a wire harness protecting portion that extends diagonally between the front side portion and the passenger compartment side portion so as to connect the bellows portion and the wire inserting through-hole. The wire harness is insertable into the wire harness protecting portion. The front side portion of the door mounting base portion may include a recessed portion on which a weather strip is mountable.
When the above-described grommet is mounted in an opening of the door body, which has little restriction to the depth thereof, and the wire harness is diagonally mounted, an area corresponding to the cross section of the wire harness can be secured to mount the wire harness, regardless of reducing the vertical width of the opening. Accordingly, the vertical width of the door mounting base portion of the grommet mounted to the door body can be short, and as a result, an area of the grommet exposed to the exterior can be reduced and the appearance can be improved. Further, due to the reducing of the vertical width, an area of the grommet over which the weather strip is mounted becomes short. Thus, the more portion of the weather strip can be mounted on the door body, and thus, the weather strip can be securely mounted, and can be prevented from separating from the door body, and waterproofness can be ensured.
In addition, since the grommet described above is provided with the door mounting base portion, the bellows portion and the automobile body mounting base portion unitarily formed in one piece as a single unit, a mounting operation can be performed easily. Further, since the wire harness W/H is covered by the wire harness protecting portion of the door mounting base portion even at the position from the front surface to the passenger compartment surface, the possibility that water will splash on the wire harness is reduced. Further, since the wire harness is diagonally mounted from the front surface to the passenger compartment surface to pass through the wire harness through-hole, the wire harness is bent at obtuse angles, and thus, an operation to insert the wire harness into the grommet can be performed easily.
Preferably, an engaging recessed portion to engage with the door body is provided in an entire periphery of the front side portion and the passenger compartment side portion, and a lip projects from an end of the engaging recessed portion about the entire periphery of the front side portion and the passenger compartment side portion. As described above, if the engaging recessed portion and the lip are provided in the door mounting base portion, the grommet, which engages with the opening (notch) of the door body, can be securely fixed by the engaging recessed portion, and waterproofness at the engaging position can be ensured by the lip.
Furthermore, preferably a drain hole is provided in the lip at the position of the recessed portion for the weather strip so that the drain hole extends between the engaging recessed portion and a bottom of the recessed portion for the weather strip. Due to the drain hole provided as described above, even if water passes through a gap between the weather strip and the grommet (or the door body), the water passes through the drain hole and is discharged into the interior of the door body via the engaging recessed portion. Thus, waterproofness can be ensured.
Preferably, a pair of drain holes are respectively provided in upper and lower lips of the door mounting base portion so that the door mounting base portion has a vertically symmetric structure. Due to the symmetric structure, the grommet for a door can be used with both right and left doors, and thus, parts can be efficiently used.
The present invention further provides a method for mounting the grommet by inserting the engaging recessed portion provided in the front side portion of the grommet into the opening in the front side of the door body along a guiding surface of the opening in the front surface, and pressing the engaging recessed portion provided in the passenger compartment side portion of the grommet into the opening in the side surface of the door body by deforming a portion of the wire harness protecting portion inwardly. According to this method for mounting the grommet, the conventional cumbersome mounting process can be avoided.